Prozac was the first of a new generation of antidepressants to come on the market. It works by enhancing the action of a brain chemical called serotonin. In a few short years this drug has become so popular that, in addition to becoming the most prescribed antidepressant on the physicians’ hit parade of drugs, it has become a household name.

This antidepressant medication has been featured on the covers of newsmagazines and has even been the subject of a best-selling book (Listening to Prozac). This success comes largely because it is less likely to cause typical side effects associated with older medications.

Tricyclic antidepressants like Elavil, Tofranil, Sinequan and Pamelor can produce dry mouth, constipation, dizziness, weight gain, and a sluggish or lethargic feeling. Prozac does not.

If anything, it has a slight stimulant action.

Prozac is used in the treatment of depression; it is also approved for treating obsessive compulsive disorder. Psychiatrists continue to experiment with the use of this medication for eating disorders and other problems.

Side Effects and Interactions

Side effects associated with Prozac include headache, nervousness, agitation, insomnia, tremor, fatigue, rash, lightheadedness, drowsiness, dizziness, depersonalization, nausea, upset stomach, diarrhea, loss of appetite, stomach pain, sweating and dry mouth.

Somewhat less common adverse reactions include impaired concentration and memory, weird dreams, lowered libido, loss or delay of orgasm, abnormal ejaculation, dry skin, constipation, hair loss and itching. Report any symptoms to your physician promptly.

Uncommon but very serious side effects to be alert for are rash with flulike symptoms such as chills, fever or sore throat, anemia, breathing problems, severe allergy, or seizures.

Prozac interacts with a number of other medications. Anyone taking other antidepressants, especially drugs such as Nardil, Marplan or Parnate should stop such a medicine at least two weeks before starting on Prozac.

If Prozac was taken first, five weeks should elapse before starting on one of these other medicines, because Prozac can last in the body a long time.

Tricyclic antidepressants like Elavil or Tofranil and even Anafranil for obsessive-compulsive disorder may have stronger actions and more pronounced toxicity when they are combined with Prozac. If such a combination is prescribed, the physician should monitor blood levels of the medications. The same is true of the antipsychotic drug Haldol.

If the amino acid tryptophan ever becomes available in this country again, it should not be taken with Prozac, as it may increase the potential for adverse reactions.

Other compounds that could cause complications in combination with Prozac include lithium, Coumadin, Lanoxin and Valium (or similar medications such as Dalmane, Halcion or Klonopin).

Interactions between the herb St. John’s wort and Prozac are possible. Switching between antidepressants and herbal treatment calls for medical guidance (physicians can find a suggested protocol for gradual substitution of St. John’s wort in Hyla Cass’s book, St. John’s Wort: Nature’s Blues Buster).

Check with your pharmacist and physician before taking any other medicines or herbs.

Special Precautions

Some people may need very close monitoring if the doctor prescribes this medication. Because this drug may cause anxiety, nervousness and insomnia in a substantial number of people, those with a predisposition to such conditions need to alert their physicians if such symptoms are aggravated by Prozac.

Patients with kidney disease, diabetes, liver problems or a history of seizures also require careful monitoring while they are taking Prozac.

People with a history of suicide attempts must also be extremely vigilant. There have been reports that some people may develop a preoccupation with suicide or violence while taking Prozac. It is still not certain whether this is caused by the underlying mental condition or is in some way related to the drug.

Family members must help monitor people on taking this medication for suicidal thoughts or self-destructive behaviors. The doctor must be notified immediately in such cases.

Taking the Medicine

According to the manufacturer, you can take Prozac with or without food. If it upsets your stomach you may find that swallowing it with meals may be helpful.

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  1. PATTI

    To Sarah:
    I have had the exact same thing happen to me. The burp, the powder,the burn. I have had this happen more than once. I tried taking the med in the morning after I eat and before bed. Time of day doesn’t seem to help. I found no pattern, and it only happens once in a while, but it is HORRIBLE!! Have you ever found an answer on this? Any additional information will help.

  2. Suella

    Wow!! This was originally published in 2000! I was prescribed fluoxetine in 2004 and just weaned myself off of it within the last three months. Issues that I thought we just pertaining to “getting older” disappeared! My stomach acid issue has stopped, my dry skin issue has stopped, my “fogginess” has cleared, and I have had the first orgasm in over 5 years! After reading the book “Lost Connections” by Johann Hari- I realized that I was prescribed an anti-depressant when I was going through a very difficult time that SHOULD have made me sad, weepy, and anxious!

    What I never did (until now) was address that issue! Instead I listened to my doctor and turned to medication to “control the symptoms”. My doctor never once asked if I had things going on in my life to cause these issues. I have never felt better and will NEVER rely on long term medications again! There are alternatives out there and find an integrative doctor that helps you get to the root of the problem- not just mask the symptoms!

  3. Samantha

    I am a little worried! I just had the same effect as Melissa in 2013, I took my medication as normal and about 5 minutes later I burped and a powder came out and went into my lungs and nose. Is this something I should be worried about? It burned so bad I’m just worried that it is going to cause problems as I have severe asthma.

  4. Kathy
    Int'l Falls MN

    I have gained some weight taking 20 mg’s of Prozac and I am wondering if I would cut it down to 5mg’s if it would be easier to lose weight.

  5. Sarah

    My son started taking fluoxetine after 2 suicide attempts. He was prescribed the drug after he first suicide attempt and the second attempt was while he was taking fluoxetine. After starting the tablets for 2 weeks I noticed a huge improvement in his mood – so much happier, laughing and making jokes. Nothing seemed to stress him out, he was totally chilled.

    Which is why the second suicide attempt come as such a shock and I worry every hour of the day, analyse his every movement. And if I try to call him while I’m out and he doesn’t answer I completely panic! Since taking the meds he’s starting acting really strange. Almost phsychotic. Making weird faces, and the other day he said he had an out of body experience where he felt like he kinda left his body. I’m concerned about this tablet now but worry about how he’ll be without it.

  6. DBarnes

    I just started taking Fluoxetine 10 mg yesterday which I am to combine with Bupropion in 4 weeks as a “cocktail” in attempt to treat major depression/generalized anxiety disorder/panic disorder that I’ve been suffering for several years. The panic disorder began 2 years ago and that made me spiral into an extremely severe agoraphobic further isolated state which has been all but impenetrable to treatment so far. In addition, I have several co-morbid conditions… Interstitial Cystitis, Fibromyalgia, neuropathy, hypothyroid, pelvic floor dysfunction, vulvodynia, as well as other ailments in which I had prior to these conditions which still weave in and out, such as migraines, allergies, IBS. Although, not diagnosed I believe I also have chronic fatigue syndrome/ME. I am extremely sensitive to medications. I develop tolerance very quickly. Within hours of taking my first dose of Fluoxetine yesterday my body tensed up and felt as if all of my pressure points throughout my body were on fire. Especially my shoulders, underarms and hips. I was very afraid to take it again today, but I did and now I’m terrified of going through the same thing again. I want to give this a good shot. I truly do. However, my body is already suffering with such pain and inflammation. The thought of taking something that heightens my suffering to any degree is terrifying and causes in all its’ irony an altogether different type of panic. A panic that rests on some edge inside. I don’t know if that makes any sense. But, I wonder if anyone else has experienced this? If anyone else is sensitive to antidepressants for whatever varied reasons? I’ve always been most sensitive to anti-depressants, save benzos, for as long as I can remember and that just seems to have worsened to impossible with the onset of all the conditions I ail with. I know this is an older thread, but any shared experience would be helpful just to know I’m not alone.

    • DBarnes

      I forgot to say thank you for any replies in advance.

  7. Sawyer R.

    I took Prozac (Teva/Pliva generic) about one year ago, and it worked wonders.

    This year my depression came back, and so I decided to resume taking it. Things were progressing great like the first time, but then my prescription was changed to Sandoz, which I only realized a few weeks later after feeling awful.

    Now I am back on the original (Pliva) but am not getting better like I did before.

    Any thoughts? And has anyone switched back to their original generic and experienced successes or failures? Thanks in advance for the responses.

  8. Yolz

    Strips your bowel lining? Thats scary. I am getting a lot of acid in my throat, doe that ever go away? Thanks

  9. John

    Have been taking 20 mg generic Prozac for years. On my most recent refill the manufacturer was changed to Sandoz. Within 2 weeks I was deeply depressed as I use to be 15 years ago before I started Prozac. Don’t understand but am changing back to my usual generic brand AUG.

    • Sawyer R.

      John, did it end up working out for you? Thanks in advance for your response.

  10. Sargrith

    Hi. I am 87 and have had several bad anxiety bouts from age 25 to having one currently. I have always struggled with them and often felt desperate leading to panic attacks The physical symptoms have mostly varied although palpitations have always been a factor to a varying degree. Constipation usually a physical symptom.

    I had banging and snapping in my earliest attack at 25 years of age at night in my head. The attacks have varied as a problem from several months to 2 years duration and then only subsided due to medication of Tofranil after the first attack in which I received no help from the doctors at all but did get blank stares. This was in 1950. At that time the average doctor hadn’t a clue how to react and medication for most was nil. However, most of my life for the main has been good. Bouts would only start at times of feeling trapped in a given predicament and could see no easy way out. I inherited it from my father who committed suicide at 44. Wish I’d had more of my mother’s genes! But what I did have has pulled me through life. Thankfully. Anxiety attacks are hell. Depression is a lot more than just feeling fed up as some who know no better think!!

  11. kal

    I was prescribed 20 mg of Prozac in early august, went back in to see my dr in late/early September because my anxiety was horrible and he upped my dosage to 40 mg and put me on 2mg Ativan and atenolol. Its been going well so far, I’m lost 23 lbs since my first appointment with this dr. I have energy, my social anxiety is almost gone.

    I don’t get all shaky and red faced when I’m in a room full of strangers. However, I’m still having major panic attacks so I’m going to see about going with Xanax instead of Ativan, I have ptsd and severe anxiety. The Prozac gives me a ton of energy, I’m always hyped up and I sweat a lot more and barely have an appetite but its giving me motivation to keep working out. If I don’t don’t take Ativan or Xanax with the Prozac I get bad insomnia. Other than that I’ve had a good experience with it.

    • Meagan
      New Hampshire

      As with you I just started this medication about a week ago and I’ve yet to feel a difference. I lost my spouse a little over a year ago and decide it was finally time to do something about it. I’m currently also on 2 mg of xanax a day cause I still have horrible flash backs of her death. She went in her sleep in bed with me and our son. Horrific! Should I be afraid of the withdrawal when I decide to come off this? I, too, have developed a social anxiety disorder since the incident. Also, I keep reading about weight loss. This scares me as I’m 5’2 and 110 lbs. I can’t lose anymore weight! Although the peppiness you all are talking about I NEED! I heard prozac blocks amphetamines such as adderall and things which is kinda weird considering the depression and anxiety I have, not only make me fatigued and with no energy, and now I’m hearing that prozac completely blocks the effects of stimulants which help me greatly. Any thoughts? I’d really appreciate getting some feedback since this definitely isn’t something you post on fb…..thank you xoxo

  12. dk

    I had problems with this brand. I was hearing voices, and suicidal thoughts….. I too am looking for a generic that works like the real thing. One is 350.00 month, the other 6.00 month.

  13. Sam

    Hi ppl. I recently started taking Prozac 40 mg r/t anxiety. Before that I had taken Effexor 75 xr roughly ten years ago for the same thing and it went away and I would take the Effexor off and on when I felt my anxiety start up. My dr that prescribed the Effexor years ago was the same one who changed me to Prozac. I saw him a week after starting it and I really felt no different. It’s been 7 weeks now and still feel anxiety throughout the day but I feel like I can concentrate more than previous at times. I’m a nurse, father.

  14. Dav

    I have been taking prozac for little over four years, It helped me soooooo much. I don‘t know where I would be without it.

  15. Deb

    I have been on and off Prozac for the last 20 years. Currently I am taking 60mg of Sandoz fluxotine and have noticed very little positive effect. It has been 4 weeks now and I am wondering about the manufacturer and how much time before the drug will work for my depression. I barely can make it to work, house is a mess, and I have suicidal thoughts occasionally. Prozac has always worked for me in the past but now I just feel lethargic and sad and disinterested in just about everything. If anyone knows specifically about the manufacturer Sandoz fluxotine please email me.

  16. E.

    Wow, lots of different experiences. Prozac was the first antidepressant I ever took, back in 1992 before it was dispensed like candy. I was in college, barely functioning, not eating, and praying for death to take me. I flew home for Thanksgiving break and my father had a psychiatrist ready to see me. She gave me Prozac and in about two days I felt a 180 degree turn. My brain chemistry was clearly a mess, and I feel it saved my life… back then I felt it was worth saving, Now, again, this was 1992, when ppl who REALLY needed it got it. Not every random person who had a bad day, I took it for some years. Orgasms damn near impossible (female). Basically it just stopped working and for 22 years or so I’ve been on various cocktails of drugs. It’s frustrating. Nothing ever gave me suicidal thoughts, because I already had them and still do sometimes.
    But, like I said, looking back I would say Prozac saved my life. I was seeking ways to end it. Unfortunately, in a half-assed fashion, I still do. And no drug is going to change that. But at least I can function.

  17. Sono

    Hello All,
    I was prescribed Fluoxetine August of 2012. At That point I had been on crutches for 8 1/2 months. (Torn ligament diagnosed as a sprain at first)But because I was injured so long, I had to move out of my nice apt and in w/ my folks till I could get back on my feet (pun intended!). My Dr. suggested trying 20 mg of Fluoxetine because I seamed depressed.(Go figure)
    I was very happy with the results. I did not notice any of the side effects (well..except the no climax thing) and it really did help with all that was going on at the time. (like squeezing an established life into my old bdrm…on crutches)
    So, back to the wrongly diagnosed foot problem. Because I had an injury that went untreated for so long I ended up W/ nerve damage in the foot. This apparently called for Gabapentin 400 mg to make it possible to walk after physical rehab did not do the trick.
    Whether it was Gabapentin alone or in combo w/ the Fluoxetine, I am having *such* brain fog. I forget words, go to get something I’m holding, shave the same leg twice, say hello all over again to someone I just greeted 3 min’s ago. This is not working for me. Sure I can walk, but I’m used to being clear minded.
    I also ‘lose time’. I’ll be washing dishes and will not be sure how much time has passed. I’ll realize that there is someone in front of me and that I may have been talking to them…but now, I’m just standing there staring at them. YES! I was talking to them… but about what… never mind, they just walked away.
    Based on this something has got to go. Since the 20th I have been taking the Fluoxetine every other day and now intend to take it every 3 days for about 2 weeks to bow out safely. Since I have been on it for quite awhile, I feel confident that it is time to get off of the prescription anyhow. I did let my Dr know about my ‘flight plan’ last month. She says the side effects I am feeling are normal. But I can not function like this.
    So far so good getting off the prescription. If I would benefit from a anti-depressant in the future, I would absolutely go back on Fluoxetine.

  18. Mona

    Does anyone else experience abnormal/weird dreams with fluoxetine??? I am being to wonder if my abnormal dreams are the cause of this pill. I am not complaining because for me they help A LOT!!! I can tell when I don’t take them. I feel the difference. I worry to though, will I be dependent on them forever now??? Guess I will cross that bridge when I get there right?!

  19. VN

    Nt don’t stop cold turkey! One every other day for a week, then 3 days. I had a horrible reaction stopping years ago and feel blessed I lived through it.

    • adam

      I already had weird dreams before starting prozac. But now my dreams are super weird and crazy. But thats okay with me cause I like dreaming. Its like living in an alternate universe. And in my dreams I have no anxiety or panic attacks. I’ll think about it but it doesn’t happen.

  20. nt

    Does any one know how long the side effect would wear off I was on 20 mg and I cut cold turkey.

    • Joanne
      United Kingdom

      I had to stop taking it after 4 weeks on it as I had really severe side effects, my doctor told me the tablets will take 5 weeks to get out of my system, I am just over 5 weeks off them now and still having severe stomach and back pain and excuse this by loose bowel movements, although thank god the sudden bowel movements I was having daily on the stuff has stopped since I went cold turkey off them. Not sure if I am having withdrawl symptoms as they are not out of my system but it is a pain, may have to go back to the docs again.

  21. Melissa

    The same thing just happened to me when I took my dose. I had some indigestion and burped and powder actually came out that looked like smoke. My throat hurts so much right now that is why I came on here to read blogs! It works well for my mental state but I do notice a major delay in orgasm and the fact that it burns my stomach and now my throat isn’t the greatest.

  22. aaa

    Hi SO,
    yes I have experienced delay of orgasm on 20-60mg of fluoxetine a day.
    It has improved over the years if I am highly aroused, it has taken a while though but it should come back even if delayed.
    I never want to come off this medication as I have my happiness back and can laugh again now (been on it 12 years)
    Good luck

  23. Mel

    I am taking 40mg of Lily Fluoxitine in the morning – the worst side effect has been extreme fatigue! I can sleep all day – it’s debilitating!

  24. AJ

    Hello all. I’m writing about possible discontinuation side effects of Prozac. After going from brand to generic to brand, I had what I can only describe as symptoms of “excess serotonin” (I know this from internet research and a previous experience bumping up the dose on my own.) I went off and felt immediately better.
    For 6 weeks I was off the 20 mg I had been taking. It was the longest I had been off of an SSRI for 15 years. I had some brain zaps, but that was about it. During that time, I took something called, “Ashwagandha”– an herb that is an adaptogen. I stopped that after a month when I doubled the dose (I had only been taking half the recommended dose at that time) and felt “weird”.
    A few days later, I tried to go back on the Prozac– 10mg/day for three days. I had what felt like a minor allergic reaction. So I stopped that was two weeks ago. So in total, 8 weeks have elapsed since I stopped the Prozac.)
    5 days ago, I got a nasty bout of diarrhea. I NEVER get diarrhea. Never. I’ve had digestion problems, but never with that. I thought it was something I ate. But 5 days later, I have gas, bloating, fullness and loose stools. I’ve had searing stomach pain.
    At this point, I’m not sure if it’s a flu bug, or discontinuation symptoms from the Prozac.
    Any ideas/thoughts/suggestions are appreciated.

    • Joanne

      It sounds like what I had taking them and also off them, my doc said it can last up to 5 weeks after stopping the tablets, although I am still getting the stomach pains and back ache and depending what I eat loose stools, a few things might help though avoid foods with fibre such as wholemeal bread and cereals and also spicy foods I found these really made everything worse, also would recommend gaviscon to help with the stomach found it helped me a lot. My doctor told me all this was caused by a reaction to the drug and what it does it strip your stomach and bowel linings which will need time to repair after the drug is totally out of your system, hope this helps.

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